Crystal Structure of an Adduct of Sarcosine with Sulfuric Acid (at 140 K)

The crystal structure of an adduct of sarcosine with sulfuric acid, (C₃NO₂H₈)₂SO²⁻₄, has been determined at low temperature (140 K). The crystals are triclinic, space group = P1 with the unit cell dimensions, a= 7.623(1) Å, b = 11.538(2) Å, c = 14.214(2) Å, α = 71.46(2)°, β = 74.36(2)°, γ = 86.46(2)°. Based on 4924 reflections with intensities larger than 3σ(I), the structure was refined to a conventional R factor of 0.038 giving e.s.d.s. in bond lengths and angles of 0.003 Å and 0.2°, respectively. There are two formula units in the asymmetric unit and both sulfate ions exist in two disordered orientations. The sulfate group 1 occupies the two orientations in the proportion 0.82/0.18 and sulfate group 2 in proportion 0.69/0.31. Both Orientations of the sulfate groups satisfy the hydrogen bonding scheme equally well. There is also a pseudo-symmetry element within the asymmetric unit as one half of this unit is transformcd into the other by a translation of approximately one half along the b- and c-axes. Thus, sarcosine molecule 1 is translated to sarcosine IV and sarcosine II to III. In the same manner, the sulfate group I in its main orientation is translated to the sulfate group 2 in its alternative orientation and vice versa.     

Crystal Growth of some Urinary Stone Constituents: I. In‐Vitro Crystallization of L‐Tyrosine and its Characterization

L ‐Tyrosine (C₉H₁₁NO₃), having morphology of spherulitic needles and long needles, an amino acid constituent of urinary stone, is crystallized in silica gel under suitable pH conditions and by single diffusion and double diffusion methods. The grown crystals were characterized by density measurement, Fourier transform infrared spectroscopy, X‐ray powder diffraction and thermogravimetric analysis.     

Crystal growth of some urinary stone constituents: II. In‐vitro crystallization of hippuric acid

Hippuric acid [C₆H₅CONHCH₂COOH], one of the organic chemical constituents of urinary stone is crystallized in silica gel under suitable pH conditions by double diffusion method. The grown crystals were characterized by density measurement, Fourier transform infrared spectroscopy, X‐ray powder diffraction and thermogravimetric analysis.     

Total Synthesis of Vancomycin Aglycon—Part 3: Final Stages

A triazene-based synthetic strategy for the construction of the complex biaryl ethers and a Suzuki coupling reaction were the key steps in the synthesis of precursor 1 of the aglycon of vancomycin, which already contains the complete skeleton of the target compound. The cleavage of the triazene unit from the D ring and the removal of the other protecting groups led to the aglycon of vancomycin. These strategies should be particularly valuable for the synthesis of other naturally occurring glycopeptide antibiotics and offer opportunities for the synthesis of combinatorial libraries of compounds of the vancomycin family for chemical biology studies.     

Infrared and Raman spectroscopic studies of L‐valinium picrate

The vibrational assignments of the observed wavenumbers have been made by analyzing the infrared and Raman spectra of L ‐valinium picrate in the crystalline state at room temperature. L ‐Valinium acts as the cation of the crystal and the carbonyl CO group exists in the protonated form in it. Asymmetric deformation and symmetric deformation modes of the isopropyl group have been identified, indicating that the two CH₃ groups are in different environments. The stretching and bending modes of the various functional groups have been shifted owing to the extensive intermolecular hydrogen bonding in the crystal. The symmetry of the picrate anion has not been modified in the crystal by the hydrogen bonding with the cation. Fermi resonance is also observed. Copyright © 2006 John Wiley & Sons, Ltd.     

Crystal Structure of Sarcosine Cadmium Chloride

Single crystals of sarcosine cadmium chloride were crystallised from a saturated aqueous solution containing stoichiomeric amounts of sarcosine and cadmium chloride, in 1:1 proportion. The intensity data were collected using a CAD-4 diffractometer with graphite monochromated MoK_α, radiation. The crystal data are as follows: a = 6.916(1) Å, b = 13.855(3) Å, c = 7.981(1) Å, V = 764.1 Å · F.W. = 272.4, d_expt = 2.39 g · cm⁻³, d_calc = 2.368 g · cm⁻³, Z = 4 and the space group is P2₁/n. The structure has been solved to an R value of 0.023 for all the 1323 reflections with I > 2σ(I). The sarcosine molecule exists as zwitterion in the structure. The conformation of the sarcosine molecule is significantly changed due to the complexation of the molecule with cadmium chloride. The cadmium ion is found to have an octahedral coordination with both the oxygens of the carboxyl group of the amino acid and chlorines taking part in it. Since the complex has no water of hydration, only two hydrogen bonds of the types N H ‥ O and N H ‥ Cl are found.